The Dawn of an Era

The efficiency of superficially porous particles (commonly referred to as SPP or “core-shell” particles) has been proven to provide fast separations with lower backpressures. This benefit helps customers achieve faster separations with their existing HPLC instruments. Coupled with small-particle technology, SPP particles also provide an efficiency boost to those running UHPLC when compared to fully porous particles. SPP particles feature a solid, impermeable core enveloped by a thin, porous layer of silica that decreases the diffusion path and reduces peak dispersion. As a result, they offer significantly higher efficiency than traditional fully porous particles of similar dimensions. Core-shell particles changed LC, but they were only the beginning....

A New Species Has Evolved

Restek is proud to announce that SPP core-shell technology has evolved with the introduction of Raptor LC columns. Although column efficiency, which is boosted with superficially porous particles, considerably accelerates analysis time, it has little effect on resolution (i.e., peak separation). Selectivity, on the other hand, has a substantial impact on resolution, but shows minimal improvement in analysis times. Raptor LC columns bond rugged 1.8, 2.7, and 5 μm superficially porous particles with Restek’s unique Ultra Selective Liquid Chromatography (USLC) phases to offer chromatographers the best of both worlds.

By being the first to combine the speed of SPP with the resolution of highly selective USLC technology, Raptor LC columns provide analysts with the most powerful tools available for fast and efficient method development. And, because they are from Restek, Raptor LC columns are backed by the manufacturing and quality systems you’ve come to trust along with the best Plus 1 service in the industry. Choose them for all of your valued assays to experience Selectivity Accelerated.

Only Raptor LC columns offer the higher efficiency of a superficially porous particleplus the improved resolution of the USLC phases.

Fully porous particles with typical stationary phases show longer retention times and less resolution.

Ordinary superficially porous particles (SPP) with typical stationary phases show shorter retention times than fully porous particles, but still exhibit less resolution.

Whether labs conducting perfluorinated alkyl acid analysis by LC use longer target analyte lists or focus just on PFOA and PFOS, the excellent peak shapes and separations achieved here result in consistent, accurate quantification in much faster analysis times. By switching to Raptor™ C18 column, labs can process more samples per hour while still meeting fluorochemical method requirements.

In general, LC-MS/MS analysis of urinary free cortisol and cortisone can provide better specificity than immunoassay-based methods. However, it is critical that the analytical column has the proper selectivity for chromatographically separating cortisol from isobaric matrix components. In the method presented here, complete separation of the target analytes and matrix interferences was obtained in a 3-minute analysis on a Raptor Biphenyl column.

Methylmalonic acid analysis is an important clinical test for diagnosing vitamin B12 deficiency as well as methylmalonic acidemia. Methods typically require extensive sample preparation, which involves significant time and expense. The LC-MS/MS method developed here offers a much simpler alternative, providing complete chromatographic resolution of isobaric analytes from the direct injection of a protein crash sample supernatant onto a Force C18 column.

Clinical diagnosis of pheochromocytoma and paraganglioma is often based on the analysis of catecholamines (epinephrine, norepinephrine, dopamine) and metanephrines (metanephrine, normetanephrine, 3-methoxytyramine) in urine. Analysis of these polar compounds using reversed-phase LC can be difficult due to limited chromatographic retention, which results in poor separation of the analytes from closely eluting matrix interferences. This method overcomes these problems by combining a simple solid phase extraction procedure with the consistent and accurate chromatographic performance of a Raptor Biphenyl column.

Highly sensitive analysis of metanephrines and in plasma is critical in the diagnosis and treatment of pheochromocytoma and paraganglioma. Here, a HILIC LC-MS/MS method was developed using a Raptor HILIC-Si column because this approach provides retention of all target compounds in highly organic mobile phases, thus providing the increased sensitivity needed to reach low detection limits. Data from linearity, accuracy, and precision testing demonstrate that accurate results are consistently obtained—even at trace levels—for these important clinical biomarkers.

Synthetic opioid drugs, such as fentanyl and sufentanil, have very high analgesic potency. Abuse of these prescription painkillers—along with a rapidly growing list of illicit analogues—is a significant public health problem. In this study, we developed a simple dilute-and-shoot method that provides a fast 3.5 minute analysis of fentanyl and related compounds (norfentanyl, acetyl fentanyl, alfentanil, butyryl fentanyl, carfentanil, remifentanil, and sufentanil) in human urine by LC-MS/MS using a Raptor Biphenyl column.

Superficially porous particles (commonly referred to as SPP or “core-shell” particles) have been proven to provide fast and efficient LC separations. These particles feature a solid, impermeable core enveloped by a thin, porous layer of silica that offers significantly higher efficiency and sensitivity than traditional fully porous particles (FPP). At launch, Raptor SPP LC columns were touted for their selectivity and for their ability to help existing HPLC customers achieve faster separations without the need to purchase UHPLC instruments. With the launch of Raptor 1.8 μm columns, this superior Raptor performance has been unleashed on your UHPLC analyses. But, what exactly does that mean? In this technical note, we will explore the benefits of using Raptor 1.8 μm LC columns in your UHPLC instrument with a focus on peak capacity, column lifetime, and selectivity.

The analysis of melamine and related compounds is critical in protecting consumers from adulterated food products. While these highly polar analytes are difficult to retain and accurately quantify on many columns, the Raptor HILIC-Si column and LC-MS/MS method shown here allow quick and complete separations, so melamine and related compounds can be accurately identified and quantified even at residual levels.

LC-MS/MS analysis of paraquat and diquat herbicides is an important tool for protecting human and environmental health. However, the ion-pairing reagents that are commonly used to improve retention, resolution, and peak shape have a negative impact on sensitivity and can contaminate the system necessitating frequent cleaning. The LC-MS/MS analysis of paraquat and diquat presented here provides complete separation and good peak response for both target analytes in a fast, 7-minute gradient run without the use of troublesome ion pairing reagents.

Mycotoxin contamination of crops is not only a public health concern, but it also has a huge impact on the global economy. This highly selective LC-MS/MS analysis of 20 mycotoxins in just 9 minutes allows scientists to accurately identify toxins, to monitor food products for contamination, and to support control strategies that prevent economic loss.

LC-MS/MS methods for folate deficiency biomarkers in plasma are complicated by the presence of matrix phospholipids and lysophospholipids. These interferences are problematic with reversed-phase LC because they can suppress response, reduce accuracy, and contaminate the MS source. Using a Raptor HILIC-Si column and the HILIC method shown here, folate deficiency biomarkers are completely separated from matrix interferences, allowing accurate determinations to be made in a fast, 5-minute analysis.

Methods for monitoring alcohol consumption biomarkers EtG and EtS are generally limited by poor retention and coelution with matrix interferences, as well as by long analysis times and short column lifetimes. The dilute-and-shoot EtG/EtS LC-MS/MS analysis developed here using the novel Raptor EtG/EtS column easily resolves EtG and EtS from matrix interferences, providing consistent, accurate results for high-throughput labs testing human urine samples for alcohol consumption.

Whether you’ve run HILIC methods before or are attempting to for the first time, there are significant differences between reversed-phase and HILIC methods that must be considered. This article addresses common problems that analysts encounter when running HILIC methods and details how to avoid them and successfully use the technique.

As the demand for testing of pain management drugs increases, many laboratories are turning to LC-MS/MS for its increased speed, sensitivity, and specificity. The methods shown here use a Raptor™ Biphenyl column because it provides fast, accurate analysis of 231 drugs and drug metabolites.

In this technical note, we will compare the performance of Raptor 5 µm superficially porous particle (SPP) LC columns to traditional 3 and 5 µm fully porous particle (FPP) LC columns. We will demonstrate how faster, more efficient analyses can be attained with greater sensitivity and reduced system pressure by switching from FPP to SPP—without altering method conditions.

Restek's Raptor™ LC columns feature superficially porous particles (commonly referred to as SPP or “core-shell” particles) and are available in both 2.7 and 5 µm particle sizes, giving analysts greater flexibility. However, it may not always be clear which particle size to choose. In this technical note, we will examine the differences in efficiency, sensitivity, and pressure between Raptor™ LC columns packed with 2.7 vs. 5 µm particles and provide advice on making the appropriate LC particle choice

One Analysis, One Column, Less than 9 Minutes for Over 60 Multiclass Antibiotics: The use of antibiotics on food-producing animals is a public health and safety concern due to the potential of generating drug-resistant bacteria. A sensitive, efficient, and reliable analytical method for different classes of antibiotics is necessary to meet regulations covering maximum residue limits (MRL) for a variety of animal tissue and food products. The Raptor™ C18 LC column is the ideal choice.

The use of pain management drugs is steadily increasing. As a result, hospital and reference labs are seeing an increase in patient samples that must be screened for a wide variety of pain management drugs to prevent drug abuse and to ensure patient safety and adherence to their medication regimen. Restek's "Big Pain" LC-MS/MS methodology features a 231-compound multiclass drug and metabolite screen that can be performed in under 10 minutes with just one column: The Raptor™ Biphenyl.

Vitamin D2 and D3 25-hydroxy metabolites are important diagnostic markers for vitamin D status, but these compounds cannot be distinguished from their epimeric forms on a C18 column. The Raptor FluoroPhenyl column provides ample chromatographic resolution for these isobaric epimers, which possess unequal bioactivities, so accurate results are generated and thus the proper diagnosis can be made.

Raptor FluoroPhenyl columns perform well in both HILIC and reversed phase modes, giving method developers the flexibility to select the mode that performs best for their specific compounds of interest. Here we use a Raptor Fluorophenyl column in HILIC mode for LC analysis of 4-methylimidazole (4-MEI). This approach provides more retention than reversed phase mode and can be applied to determining 4-MEI levels in caramel colorings to monitor formulations and also in foods and beverages to assess potential exposure.

When we engineered our superficially porous particle (SPP or "core-shell") Raptor LC columns, we developed the bonding chemistries that are best suited to both the SPP construction and our highly selective USLC phases. But we didn't stop here. Take a closer look at a new species as we dissect the upgraded hardware and new, proprietary packing techniques behind Raptor LC columns and Raptor EXP guard columns. (PDF - 0MB)

Every LC lab has a cache of C18s, but every C18 is not created equal. When you need a general-purpose LC column, don't just grab any C18. Choose the speed, efficiency, and long-lasting ruggedness of the new Raptor C18. (PDF - 0MB)

One Analysis, One Column, Less than 9 Minutes for Over 60 Multiclass Antibiotics: The use of antibiotics on food-producing animals is a public health and safety concern due to the potential of generating drug-resistant bacteria. A sensitive, efficient, and reliable analytical method for different classes of antibiotics is necessary to meet regulations covering maximum residue limits (MRL) for a variety of animal tissue and food products. The Raptor C18 LC column is the ideal choice. (PDF - 0MB)

Raptor Speed, Efficiency, and Ruggedness—in C18: Every LC lab has a cache of C18s, but every C18 is not created equal. When you need a general-purpose LC column, don’t just grab any C18. Choose the speed, efficiency, and long-lasting ruggedness of the Raptor C18 (PDF - 0MB)

Ahead of the Curve for Large, Multiclass Lists by Mass Spec: Designed and intended specifically for use on LC-MS/MS systems, the Raptor™ ARC-18 SPP LC column offers a well-balanced retention profile without the drawbacks of using an ordinary C18 in the harsh, acidic mobile phases needed for mass spectrometry (MS). (PDF - 0MB)

Fast, Rugged Raptor Columns with Time-Tested Selectivity: The industry-leading Biphenyl, first introduced by Restek in 2005, is our most popular LC stationary phase because it is particularly adept at separating compounds that are hard to resolve or that elute early on C18 and other phenyl chemistries. As a result, the rugged Raptor Biphenyl column is extremely useful for fast separations in bioanalytical testing applications like drug and metabolite analyses, especially those that require a mass spectrometer (MS). (PDF - 0MB)

Restek's Raptor FluoroPhenyl phase gives you the flexibility to run in reversed-phase or HILIC modes so you can use the mode that is best for your target analytes. The Restek Raptor FluoroPhenyl column is also amenable to LC-MS because it is extremely reliable and efficient with acidic mobile phases. (PDF - 0MB)

Restek has now extended the speed and reliability of Raptor column technology into the HILIC realm with the addition of Raptor FluoroPhenyl columns. Restek's Raptor FluoroPhenyl phase offers chromatographers the ability to run in reversed-phase or HILIC mode for a variety of compounds. The Restek Raptor FluoroPhenyl column is also amenable to LC-MS because it is extremely reliable and efficient with acidic mobile phases. (PDF - 0MB)

Restek's Raptor superficially porous particle (SPP) LC columns are available in both 2.7 and 5 µm diameter particle sizes. This selection gives you greater flexibility to tailor your column to the task at hand—and our infographic takes the deliberation out of choosing the most appropriate size for your specific assay! (PDF - 0MB)

Typical methods for EtG and EtS analysis have several limitations: poor resolution
from matrix components, long run times that limit sample throughput, and short
column lifetimes. Restek’s new Raptor EtG/EtS column consistently retains and
resolves EtG and EtS from matrix interferences, providing fast, accurate, and reliable
results injection after injection. (PDF - 0MB)

Raptor LC columns combine the speed of superficially porous particles (i.e., SPP or “core-shell”) with the resolution of highly selective USLC technology. The sterically protected ARC-18 phase was designed and intended specifically for use with acidic mobile phases on LC-MS/MS systems. Even after extended use in low-pH (≤ 2.0) conditions, it offers consistent and well-balanced retention, peak shape, and response. Choose Raptor ARC-18 columns for the rapid analysis of large, multiclass assays by mass spectrometry. (PDF - 0MB)